Opening the book…
The water you boil pasta and green vegetables in is your one chance to season them from the inside, and most people waste it by adding a timid pinch or none at all. Pasta cooked in unsalted water is bland to the core, and no amount of sauce truly rescues it, because the noodle itself has no seasoning. The same is true of blanched broccoli or beans: salted water seasons them as they cook and, for green vegetables, actually helps them keep their color. This is nearly free seasoning that happens while you do nothing, and skipping it means starting every bite one step behind. The water should taste pleasantly salty, like seawater, not like a light suggestion of salt.
Bring a large pot of water to a rolling boil, then add salt generously and stir to dissolve before the food goes in. Taste the water; it should taste distinctly of salt, and most people drastically under-do this. Do not salt to season the water for its own sake but to season the food passing through it. Reserve a cup of the starchy pasta water before you drain, because it is liquid gold for loosening and binding a sauce. Do not rely on the sauce to carry all the seasoning; a well-salted boil means the pasta arrives already tasting good.
Water: 4 litres per 500 g pasta
Salt: about 1 heaped tablespoon (10–15 g)
Taste it — pleasantly of the sea, not bitter
Salt AFTER it boils, stir to dissolve
Reserve a mug of the water before draining
Never oil the water; it just slicks the noodlesIf you plan to reduce the cooking liquid into a sauce, salt it more cautiously, since it will concentrate. Very starchy uses where the water becomes the dish, like risotto stock, follow their own seasoning logic. And salt does slightly raise the boiling point and can affect delicate poaching, so match the salting to the method.